Figure 2.

Steady-state Ca²⁺ binding affinity for CaM. (A) Ca²⁺ affinities were determined by titrating Ca²⁺ into CaM in the absence of polymers (black) and in the presence of 20% ficoll-70 (blue) or 20% dextran-10 (green). (B) Ca²⁺ affinities were also determined in the presence (red) or absence (black) of 20% sucrose. Representative fluorescence intensities for each condition are plotted as a function of [free Ca²⁺], fit with a Hill function (solid lines), and normalized such that the fits spanned intensities from 0 to 1. To see this figure in color, go online.